BIOL-1406 Lecture 2 Exam Review

Potential Energy

location/structure

Kinetic Energy

Movement/ Vibrational

What does chemical behavior of the atom look like?

Distribution of electrons

Where are the valence electrons located?

In the outermost shell

What do incomplete atoms do with others?

Share valence electrons

When atoms stay closer through attraction, that results in a

Chemical Bond

Covalent bond

sharing of electrons to form electron pairs between atoms

Each ______ shared counts as a valence shell

electron

Molecule

2 or more atoms held together by a covalent bond

Structural formula

notation representing atom and bonding

Electronegativity is the

atoms attraction

Oxygen is a high

electron attraction

nonpolar covalent bond

atom share the electron equally

polar covalent bond

one atom is more electronegative, and the atoms do not share the electron equally

What happens when there is an unequal share of electrons?

Can cause a partial charge for an atom

What can strip atoms from their bonding partner?

Electrons

After the transfer of an electron

both atoms have charges

Ion

a charged atom/ molecule

Cation

positive charge

Anion

negative charge

ionic bond

attraction between an anion and a cation

ionic compounds

compounds FORMED by ionic bonds

What is the strongest bond?

Covalent Bonds

Most cells are surrounded by water, and cells
themselves are about ____ water

70-95%

Weak Bond

Ionic & Hydrogen

• reinforces shape of large molecules

Hydrogen Bond

forms when hydrogen atoms and electronegative (electronegativity)

Molecular shape is

important and is determined by position in the atom’s valence orbitals

Which bond do s & p and blend in?

Covalents (creates shape)

Evaporative Cooling

when a liquid’s surface remains cool (liquid → gas)

heat vaporization

heat that fluid has to absorb to become gas

What does evaporative cooling help maintain?

Temperature

Why does ice float?

Because of hydrogen bonds being ordered (less density)

What temperature does water reach at great density?

4 degrees C

Solution

solute + solvent

solute

substance being dissolved

solvent

substance doing the dissolving

What compound is flexible due to polarity?

water

Hydration shell

when ionic is dissolved in water causing a surrounding sphere

Can water dissolve non-ionic compound?

Yes and so can large polar molecules

Are oil molecules hydrophobic and why?

Yes, because of non polar bonds

Where do most biochemical reactions occur?

In water

What do chemical reactions depend on?

Combined molecules & concentration of solutes

Molecular mass

Sum of all mass every atom in a molecule

What is the number of moleclues?

1 mole= 6.02 × 10²³= 1 g

Molarity

solute per litre of solution

Only other planets that contains water is

Mars

Hydrogen atoms between 2 water molecules can

move

Hydrogen starts as electrons and transfers into

protons

Extra proton symbol

Hydronium ion (H3O+)

Losing proton symbol

Hydroxide ion (OH-)

What depends on biological molecules’ interaction?

The shape

Chemical reactions

make and break bonds

Reactant happens

at the beginning

Product happens

at the end

Are chemical reactions reversible?

Yes

Chemical equilibrium

equal reaction rate

Polar molecule

has a charge on one side of the molecule, that is not cancelled out

Polarity

hydrogen bonds w/each other

4 Properties of Water

1.) Cohesive Behavior

2.) Moderate temperature

3.)Expansion upon freezing

4.) Dissolver

Cohesion

hydrogen bond holding water together (helps transport water)

Can change in H+ & OH- affect the cell?

Yes

Concentration of H+ and OH- are ____ in PURE WATER

equal

What two substances modify concentration?

Acids & Bases

What do biologist use to determine acids/bases?

pH scale

Acids: increase or decrease?

increase

Bases: increase or decrease?

decrease

What does constant concentration look like (H+ & OH-)?

any solution at 25 degrees C

pH can be defined by

negative log of H+

Neutral pH equation

pH= -(-7) → 7

What is the equivalent of [H+]?

10 ^-7

Acid pH is less

than 7

Base pH is greater

than 7

pH ranges from which number?

6-8

What is the internal pH of most cells?

pH 7

Buffers

minimizes change

What do buffers consist of?

acid-base pairs and is reversibly combined with H+

When burning fossil fuels

CO² is the main product

What percent of human CO² is absorbed by the ocean?

25%

Ocean acidification

CO² dissolved in sea H2O→ carbonic acid

Organic Chemistry

study of compounds containing carbon

What is the compounds range?

simples molecules → colossal

What element do most compounds contain?

hydrogen

Oparin-Haldane Hypothesis (6 keys)

Methane, Ammonia, Carbon dioxide, nitrogen, hydrogen gas, water

Stanley Miller’s (Harold Urey) classic experiment

the ability to create organic molecules like amino acids (the building blocks of life) from simple inorganic compounds

Electron configuration is the key to what characteristics?

atoms

The valences of carbon and its most frequent partners (hydrogen, oxygen, and nitrogen) are

the building code that governs the architecture of living molecules

What does electron configuration determine?

 the kinds and number of bonds an atom will form with other atoms

Hydrogen

1 valence electrons

Oxygen

2 valence electrons

Nitrogen

3 valence electrons

Carbon

4 valence electrons

The ______ of carbon gives it covalent compatibility with many different elements

 electron configuration

What forms the skeletons of most organic molecules?

carbon chains

Hydrocarbons

organic molecules consisting of only carbon and hydrogen

What organic molecule is known for hydrocarbons?

fat

What does differing effects of enantiomers?

 demonstrate that organisms are sensitive to even subtle variations in molecules

Functional groups

components of organic molecules that are most commonly involved in chemical reactions

Hydroxyl

polar →hydrophilic & alcohol

Carboxyl

acid→ hydrophilic

Amino

base→hydrophilic